BEIJING, March 19 (Xinhua) -- China's auditing authorities said on Monday that 491 million yuan (77.84 million U.S. dollars) had been embezzled from the Beijing-Shanghai High-speed Railway project.

In a report based on an audit conducted between June and September in 2011, the National Audit Office (NAO) listed some irregular practices in the construction and management of the project.

Purchases that were not made through standard bidding involved 849 million yuan, while the cancellation of wind-shielding barriers construction in some sections meant 413 million yuan of purchasing funds was not used, according to the report.

As of the end of May last year, construction companies for the Beijing-Shanghai High-speed Railway held 8.251 billion yuan in arrears, 5.879 billion to material suppliers and 2.372 billion to construction labors, the report said.

After three years' construction, the 1,318-kilometer railway linking Beijing and Shanghai went into operation in June last year.

China plans to invest 217.6 billion yuan on the project and investment made by June last year totaled 196.27 yuan, the NAO said.

The final cost is yet to be known as some investment changes have not been confirmed, the report said.